Device for automatic selection of disc cams for composite zigzag patterns in sewing machines



p 9 KEIZO YANAGIBAYASHI 3,339,508

DEVICE FOR AUTOMATIC SELECTION OF DISC CAMS FOR COMPOSITE ZIGZAG PATTERNS IN SEWING MACHINES Filed March 15, 1965 4 Sheets-Sheet 1 p 5, 967 KElZO YANAGIBAYASHI 3,339,503

DEVICE FOR AUTOMATIC SELECTION OF DISC CAMS FOR COMPOSITE ZIGZAG PATTERNS IN SEWING MACHINES Filed March 15, 1965 4 Sheets-Sheet p 1967 KEIZO YANAGIBAYASHI 3,339,503

DEVICE FOR AUTOMATIC SELECTION OF DISC CAMS FOR COMPOSITE ZIGZAG PATTERNS IN SEWING MACHINES Filed March 15, 1965 4 Sheets-Sheet 3 OFIG.3

p 1967 KEIZO YANAGIBAYASHI 3,

DEVICE FOR AUTOMATIC SELECTION OF DISC CAMS FOR COMPOSITE ZIGZAG PATTERNS IN SEWING MACHINES Filed March 15, 1965 4 Sheets-Sheet 4 FIG. 4

United States Patent 3,339,508 DEVICE FOR AUTOMATIC SELECTION OF DISC CAMS FOR COMPOSITE ZIGZAG PATTERNS IN SEWING MACHINES Keizo Yanagibayashi, Hamamatsu-shi, Japan, assignor to Rhythm Friend Seizo Kabushiki Kaisha, Shizuoka-ken, Japan, a joint-stock company of Japan Filed Mar. 15, 1965, Ser. No. 439,835 Claims priority, application Japan, July 22, 1964, 39/ 41,625 2 Claims. (Cl. 112158) ABSTRACT OF THE DISCLOSURE The invention is directed to a zigzag sewing macihne of the type having a moving part and a needle bar oscillating mechanism, and including a built-in unit for automatically selecting disc cams for composite zigzag pattern stitching, such unit being defined by a group of needle position changing cams, a group of amplitude changing cams, groups of cam followers respectively corresponding to said cams, transmission means driven by the moving part for transmitting movements controlled by the cam followers to the needle bar oscillating mechanism, and a group of patterned selection tappet cams for selectively placing at least one of the cam followers into an operative condition with the group of tappet cams being rotated for effecting automatic and simultaneous changing of needle position line and amplitude thus causing automatic stitching of a wide variety of composite zigzag stitching patterns.

This invention relates to so-called zigzag sewing machines and more particularly to a new device for automatically selecting disc cams for composite zigzag stitching patterns in sewing machines.

Briefly stated, the present invention relates to a device in the form of a built-in mechanism within a zigzag sewing machine provided with a needle bar oscillating mechanism and essentially comprising, in combination, a group of needle position changing earns, a group of amplitude changing cams, groups of respectively corresponding cam followers, a transmission mechanism through which movements of the cam followers are transmitted to said needle bar oscillating mechanism, and a group of selection tappet cams for selectively placing one or more of the cam followers in operative condition, the group of selection tappet cams being rotated to effect, automatically, simultaneous changing of needle position line and amplitude, thereby to accomplish automatic stitching of a wide variety of composite zigzag stitching patterns.

It is an object of the invention to provide a device of the above stated character having a relatively simple construction and simple and easy operation.

It is another object to provide a device of the above stated character whereby, by the manipulation of a single pattern selection dial, composite selection of automatic cams is possible in a centralized, unified, and instantaneous manner.

It is a further object to provide a device of the above stated character having various advantageous features of construction whereby smooth operation can be obtained and switching between automatic and manual operation can be effected in a simple manner without special accessory means.

Other objects and unique advantage of the invention will become apparent from the following description.

Generally described, the device according to the invention has the following essential features. The rotational pivots of a large number of cam followers corresponding to the aforestated groups of amplitude changing cams and needle position changing cams are aligned on a single line, and these pivots are disposed in layer arrangement in a respectively independently suspended condition on a group of engagement actuating arms also in layer arrangement.

On one hand, there is provided a pattern selection tappet cam wheel supporting on its outer periphery a group of a large number of tappet cams of different operational widths, and the tappet cam group is adapted to select one or, simultaneously, a plurality of the engagement actuating arms corresponding to a preset composite pattern. By rotating this tappet cam wheel, one or a plurality of the engagement actuating arms are selected and lifted in a unified manner to cause needle position cam followers and amplitude cam followers to be simultaneously engaged in operational condition and, moreover, to effect in a unified manner the changing of the composite pattern stitching and the engagement and disengagement into and from the inoperative condition of the cam follower groups.

The specific nature, principle, and details of the invention will be more clearly apparent by reference to the following detailed description with respect to a preferred embodiment of the invention when taken in conjunction with the accompanying drawings throughout which like parts are designated by like reference characters, and in which:

FIGURE 1 is a partial elevational view, partly in section as viewed from the operators position, of a sewing machine arm in which the automatic cam selection device according to the invention is installed;

FIGURE 2 is a partial plan view corresponding to FIG URE 1, showing the essential parts of the device of the invention;

FIGURE 3 is a partial sectional view taken along the plane indicated'by line III--III in FIGURE 2 a viewed in the arrow direction;

FIGURE 4 is a combined sectional view taken along the planes indicated by lines IVaIVa, IVb-IVb, and IVc-IVc in the directions of the arrows; and

FIGURE 5 is a perspective view showing a state of the selection tappet cam wheel.

Throughout this disclosure, the terms such as front, rear, left, right, up, and down, and related terms indicate directions as viewed from the position of the operator of the sewing machine, the front of the sewing machine being that side thereof facing and disposed nearest the operator.

Referring to the drawings, a triangular (triple-lobe) cam 5 is rotated by the rotation of a main shaft 2 rotata'bly supported horizontally in an arm 1 of a sewing machine with a top cover 67, with said rotation being transmitted through a gear 3 and a gear 4 meshed perpendicularly therewith. The rotation of the triangular cam 5 causes oscillatory motion of an oscillating yoke 6 engaged thereabout, and said oscillatory motion is transmitted through an amplitude regulator 7 to cause oscillation of a needle bar oscillating frame, whereby zigzag stitching is accomplished.

A phase arm frame 8 of frame shape is pivotally sup ported relative to the arm 1 by a pivot shaft 9. The ampli tude regulator 7 is pivoted on the end of a rear arm 10 of the frame '8, and an amplitude actuated arm 12 is rotatably pivoted at 13 on the end of a front arm 11. An upper arm 14 of the regulator 7 and the end of the amplitude actuated arm 12 are connected at 16 and 17 by an amplitude transmitting bar 15, and a left arm 18 of the regulator 7 and the end of a zigzag coupling arm 19' pivotally supported on the pivot shaft 9 are indirectly coupled by a zigzag regulating link 20, whereby a parallel four-bar linkage is formed by the four links consisting of the link 20, the phase arm frame 8, the zigzag coupling arm 19, and the left arm 18 of the regulator 7.

The phase arm frame 8 has a right arm 21 to which there is fixed a phase arm bar 22. The extreme end of this bar 22 is pressed against a manual operation position line cam 23. The zigzag regulating link and the zigzag coupling arm 19 are connected by a connecting pin 24 which is engaged by the tines of of a zigzag arm yoke 25. The base part of this yoke 25 is supported pivotally on a pivot shaft 26 supporting the triangular cam 5. The right-hand tine 27 of the yoke 25 is extended and is engaged with a pin 29 on a zigzag manual control arm 28 fixed to the pivot shaft 9.

A phase arm pin 29' is imbeddedly fixed at one end to the rear arm 10 of the phase arm frame 8 and is engaged by yoke tines 30' at the lower end of a phase connecting arm 30 of bent form which is pivoted by a shaft pin 31 to the rear wall of the sewing machine arm 1. At the other end of the arm 30, there is fixed by means 33 a phase transmitting bar 32 of a length suitable for engaging the required number of needle position cam followers described hereinafter.

A phase arm tension spring 35 is fixed at one end to right-hand part 34 of the phase arm frame 8 thereby to exert constantly an elastic force tending to rotate the pivotal point of the amplitude regulator 7 on the arm frame 8 in the counter-clockwise direction (direction toward the left of the needle baseline). An amplitude tension spring 36 is fixed at one end to the upper end of the zigzag arm yoke 25 thereby to exert, by way of the engagement between the yoke 25 and the zigzag regulating link 20, a force tending elastically to rotate the zigzag regulator 7 in the counter-clockwise direction (direction of zero amplitude).

A worm 37 fixed to the main shaft 2 is meshed with a worm wheel 38, and the gear ratio is of the require-d value. On respective sides of this worm wheel 38, which rotates about a horizontal, front-to-rear axis, there are provided in parallel, laminar arrangement the required number of needle position changing earns 39,, 39 39,, and amplitude changing earns 40,, 40 40,,, the subscript designations indicating the sequential order from the rear toward the front. These cams are supported coaxially on a cam shaft 41 which is rotatably supported by the arm 1, and to which the worm wheel 38 is fixed, and are fixed thereto by a key 42, whereby the cams are rotated at reduced speed 'by the worm wheel 38.

A suitable number of needle position cam followers 43,, 43 43,,, which are disposed to confront the needle position changing cam group 39,,, respectively have phase transmitting arms 44,, 44 44,, extending upwardly and confronting the aforementioned phase transmitting bar 32 in parallel arrangement. The transmitting arms 44 are respectively provided with tension springs 45,, 45 45,, whereby the needle position cam followers 43 are prepared for following with elastic force their respective needle position changing cams 39. At the same time, arms extending leftwardly from the followers 43 and constituting stop arms 46,, 46 46,, are prepared for contacting, with elastic force, respective engagement actuating arms 47,, 47 47,, described hereinafter.

Similarly, a suitable number of amplitude cam followers 48 48 48,,, which are disposed to confront the amplitude changing cam group 40 40 40,,, respectively have amplitude transmitting arms 49,, 49 49,, extending downwardly and contacting in parallel arrangement the amplitude transmitting bar 15. The followers 48 respectively have upwardly extending arms 50,, 50 50,, provided respectively with tension springs 51,, 51 51,, whereby the amplitude cam followers 48 are prepared for following with elastic force their respective amplitude changing earns 40. At the same time, stop lugs 52,, 52 52,, formed on the amplitude transmitting arms 49 are prepared for elastically contacting engagement actuating arms 47,, described hereinafter.

The needle position cam followers 43,, and amplitude cam followers 48,, are rotationally supported at points 53 53 53,,, which are pivotal points in a condition of suspension by engagement actuating arms 47,, 47 47,,. The arms 47,, are lever shaped and are independently rotatable about an actuating arm shaft 56 supported horizontally front-to-rear by brackets 54 and 55 which are fixed to the machine arm 1, and said arms 47,, are disposed in parallel, laminar arrangement. The actuating arms 47,, are provided on their left ends with tappet arms 58,, 58 58,, for contacting a selection tappet cam wheel 57 described hereinafter and on their upper left parts with arms 59,, between which and a spring anchor plate 63, springs 60,, 60 60,, are stretched, whereby the tappet arms 58,, are prepared for constantly contacting with elastic force and following the selection tappet cam wheel 57.

The selection tappet cam wheel 57 is supported by and fitted onto a pivot shaft 61 extending horizontally in the front-to-rear direction and is adapted to be rotatable with angular locked positions spaced at equal intervals of angle. This cam wheel 57 has a hollow cylindrical shape and is provided on its outer surface with projecting tappet earns 62,, 62 62,, which have constant shifts (cam lifts) and different operational widths in the circumferential direction, and which are provided in groups 62,, 62,", etc., 62 62 etc., 62,,', 62,,", etc., and said groups are in respective cross-sectional planes in positions confronting respective tappet arms 58,, 58 58,,, and each group in one cross-sectional plane consists of one or more cams.

For each locked position of the selection tappet cam wheel 57, the corresponding tappet cams 62 62 62,, operate in unison to lift simultaneously by a constant lift distance one or more of the respective tappet arms 58,, 58 58,,.

The aforementioned springs 60,, 60 60,, are anchored at their stationary ends by a spring anchor fixture 63 fixed to the machine arm 1. Similarly, the aforementioned springs 51,, 51 51,, are anchored by a fixture 64.

The aforementioned engagement actuating arms 47,, 47 47,, are respectively provided with spacer plates 65,, 65 65,, fixed to their sides in an arrangement such as to establish correct spacing for smooth operation without mutual interference of the needle position cam followers 43,, 43 43,, and amplitude cam followers 48,, 48 48,,. At the same time, these spacer plates 65,, serve to prevent wobbling of the arms 47,,. The engagement actuating arm group 47,, is divided into front and rear sub-groups by a collar 66 fixed to the shaft 56.

The selection tappet cam wheel 57 is caused by gears 68 and 69 to rotate with definite locked positions spaced at equal angular intervals, and the shaft 70 of the gear 69 is provided with a pattern selection dial 71 fixed thereto.

The essential elements of the automatic device for composite cam selection of the above described construction according to the invention operate interrelatedly in the following manner.

The pattern selection tappet cam wheel 57 is provided with an outer peripheral region which is parallel to its shaft 61 at parts on the outer periphery where there are no projecting tappet cams 62 62 62,,, that is, an inoperative cam base circle part 57N. When the tappet cam wheel 57 is in its locked position for causing the tips of the tappet arms 58,, to press against this cam base circle part 57N (since the upper arms 59,, are pulled by the springs 60,,), the pivots 53,, 53 53,, of the amplitude cam followers 48,, and the needle position cam followers 43,, at the end of the engagement actuating arms 47 are all lifted elastically in the upward direction. At the same time, the stops 46,, and 52,,, respectively, of the needle position cam followers 43,, and the amplitude cam followers 48,, are respectively elastically stopped (being pulled by the springs 51,,) against the lower edges of respective engagement actuating arms 47,,. Accordingly, the ends of the needle position cam followers 43,, and the amplitude cam followers 48,, are all held in positions clear of the outermost periphery of the needle position changing earns 39,, and the amplitude changing cams 40,,.

The above described condition is that for the case of manual pattern stitching, and since the needle position cam followers 43,, and the amplitude cam followers 48,,

' do not contact and follow the needle position changing earns 39,, and the amplitude changing cams 40,, irrespective of the manner in which both the manual zigzag control arm 28 and the manual position line came 23 are ro tated, it is possible to carry out manual pattern stitching.

Then, if the desired stitching pattern is selected, and pattern selection dial 71 is accordingly turned to change the operation to automatic pattern stitching, the pivot shaft 61 will be rotated through gears 69 and 68, and the selection tappet cam wheel 57 fixed by a key to the shaft 61 will be rotated to a locked position at which the outer peripheries of its tappet cam 62,, are confronting their respective tappet arms 58,, In this case, in accordance with the rotation of the selection dial 71, the tappet arms 58,, ascend and descend as they elastically follow the curve of the selection tappet cams 62,, under the force of their respective springs 60,,, that is, as they elastically follow the peripheries along the cam base circle part 57B and the peak circles of the tappet earns 62,, of the tappet cam wheel 57.

In this manner the tappet cam wheel 57 is rotated to its selected locked position at which the required plurality of tappet arms 58,, are lifted and pressed against the peak circles of their respective tappet cams 62,,, whereby the right-hand ends of the required plurality of engagement actuating arms 47,, descend, and the required needle position cam followers and amplitude cam followers 48,, are lowered to positions of readiness for elastically contacting and following their respective needle position changing cams 39,, and amplitude changing cams 40,,. These cam followers 43,, and 48,, so readied then elastically follow the cam curves of their respective earns 39,, and 40,, as these cams rotate at reduced speed, whereby the cam followers 43,, and 48,, are caused to rock about their pivots 53.

Although the cam followers 43,, and 48,, are caused elastically by the springs 51,, to contact their respective changing cams 39,, and 40,,, their pivots 53,, are held in set position without displacement because the springs 51,, are designed to exert tension forces which are much lower than those of the springs 60,, acting on the engagement actuating arms 47,,, which are thereby firmly held without movement even when the cam followers 43,, and 48,, undergo rocking motion.

When the phase arm bar 22 is fixed at the position of the left position curve of the manual position cam 23, the pivot of the amplitude regulator 7 of the phase arm 8 is caused by the spring 35 (being pulled in the direction of arrow L in FIG. 3) to be in elastic contact with the left position line and the phase connecting arm 30 is also caused, through engagement between the phase arm pin 29 and the yoke tines 30', to'be in elastic contact with the left position line.

At the same time, in accordance with the oscillation of the needle position cam followers 43,,, their phase transmitting arms 44,, oscillate, pressing against the phase transmitting bar 32, and the phase connecting arm 30 oscillates about the shaft pin 31. Through the engagement between the yoke tines 30' and the phase arm pin 29, the phase arm 8 oscillates automatically about the pivot shaft 9 in the directions of the arrows L and R against the force of the phase arm spring 35. In accordance with the minimum and maximum lifts of the needle position changing cams 39,,, the phase arm 8 is so set as to oscillate from the left position line to the right position line.

The amplitude cam followers 48,, elastically contact and follow their respective amplitude changing cams 40,, along their cam curve from minimum to maximum lift. In accordance with the oscillations of these cam followers 48,,, the amplitude transmitting arms 49 oscillate about the rotational pivots 53,, and cause oscillation of the amplitude transmitting bar 15 in elastic contact with the lower ends of these transmitting arms 49,,. As a result, the amplitude regulator 7 and the amplitude actuated arm 12 integrally assembled with the transmitting bar 15 oscillate about shaft pin 7' and pivot 13 (in the direction of arrow W in FIG. 1) during the interval corresponding to the operation of the amplitude regulator 7 from zero amplitude to maximum amplitude, whereby the amplitude is'automatically induced.

The amplitude regulator 7 is constantly pulled in the zero amplitude direction by the force of the amplitude tension spring 36 applied through the engagement 24 of the zigzag arm yoke 25 and the zigzag regulating link 20 and the articulated coupling between the link 20 and the zigzag regulator 7 and zigzag coupling arm 19. Accordingly, in accordance with the automatic oscillations of the amplitude cam followers 48,,, the zigzag regulator undergoes automatic oscillation in an accurate follow-up manner. A

Thus, by turning the selection tappet cam wheel 57, a plurality of needle position cam followers 43,, and amplitude cam followers 48,, are selectively and simultaneously placed in engagement and actuation state, whereby automatic changes of needle position line and amplitude are accomplished simultaneously. As a result, the combination of both change actuations are automatically effected, and a preset composite pattern can be stitched unitarily. Moreover, the changing of the composite stitching pattern and the switching over to manual pattern stitching by disengaging and releasing all of the needle position cam followers 43,, and amplitude cam follower 48,, so as place these followers in their inoperative state is accomplished by a single rotation of the selection tappet cam wheel 57.

By the device according to the present invention as described above, composite selection of automatic cams is accomplished unitarily and instantly by the manipulation of only a single pattern selection dial, and, moreover, the variety of stitching patterns which are composed by automatic changing of the needle position line and amplitude is greatly increased. Since only the selected cam followers follow their respective cam surfaces, the operation is smooth. Furthermore, the switching between automatic stitching and manual stitching does not require a separate accessory device as in known devices. Therefore, as an automatic composite cam selection device, the device according to the present invention greatly increases the utility and versatility of'zigzag sewing machines.

It should be understood, of course, that the foregoing disclosure relates to only a preferred embodiment of the invention and that it is intended to cover all changes and modifications of the example of the invention herein chosen for the purposes of the disclosure, which do not constitute departures from the spirit and scope of the invention as set forth in the appended claims.

What I claim is:

1. In a zigzag sewing machine having a moving part and a needle bar oscillating mechanism, a built-in device for automatic selection of disc cams for composite zigzag pattern stitching, said device comprising a group of needle position changing cams, a group of amplitude changing cams, groups of cam followers respectively corresponding to said cams, transmission means driven by said moving part of the sewing machine to transmit movements controlled by said cam followers to said needle bar oscillating mechanism, and a group of pattern selection tappet cams for selectively placing at least one of said cam followers in operative condition, said group of tappet cams being rotated to effect automatic and simultaneous changing of needle position line and amplitude, thereby to cause automatic stitching of a wide variety of composite zigzag stitching patterns.

2. In a zigzag sewing machine having a moving part, machine arm and a needle bar oscillating mechanism, a device for automatic selection of disc cams for composite zigzag pattern stitching comprising: a required number of engagement actuating arms pivotally supported in laminar coaxial arrangement on a horizontal shaft supported by said machine arm, each of said actuating arms being formed at one end thereof as a tappet arm; a pattern selection tappet cam wheel of cylindrical shape capable of rotating through equal angular intervals terminating in locked positions, said wheel being rotatable about a horizontal axis fixed to the machine arm and having on its outer surface along its axial direction a plurality of tappet cams of disc shape in coaxial laminar arrangement, each having, on its peripheral part, a number ranging from one to a plurality of projecting lobes of constant cam lift but different operational widths in the circumferential direction, said tappet cam wheel further having in its axial direction at one part on its outer surface, an inoperative cam base circle part having no projecting tappet cam, said tappet cams being adapted to actuate respective tappet arms of said engagement actuating arms, whereby said tappet arms of a number ranging from one to a plurality are simultaneously lifted in accordance with a preset pattern of simultaneous change of needle position line and amplitude when said tappet cam wheel is rotated, thereby selecting and engaging unitarily the corresponding engagement actuating arms; needle position cam followers and amplitude cam followers of the same total number as said engagement actuating arms, said cam followers being articulately connected in an independently oscillatable manner to the other ends of respective engagement actuating arms by oscillation pivots which are in suspended condition at said ends and are caused to undergo upward and downward displacement in accordance with movements of the respective actuating arms, each of said amplitude cam followers being integrally formed with an amplitude transmitting arm extending from the corresponding oscillation pivot, and each of said needle position cam followers being integrally formed with a phase transmitting arm; needle position changing cams and amplitude changing cams corresponding in number and position to respective position cam followers and amplitude cam followers, said cam followers becoming inoperative by being displaced clear of the maximum lift circle of said cams when their oscillation pivots are in positions of said upward displacement and becoming operative by being pressed by spring force toward the minimum lift circle of said cams to follow the cam curves of said cams when their oscillation pivots are in positions of said downward displacement; a phase transmitting bar fixed to a phase connecting arm and constantly contacted by said phase transmitting arms of the needle position cam followers, said phase connecting arm constituting one arm of a centrally pivoted lever, the other arm of which is provided with a yoke end engaging a phase arm pin; a pivoted phase arm to which said phase arm pin is fixed, and which is caused to oscillate by oscillations of said phase connecting arm transmitted through said yoke and phase arm pin; and an amplitude regulator supported on the end of said phase arm and provided with an amplitude transmitting bar against which all of said amplitude transmitting arms are contacting, said amplitude regulator being driven by said moving part of the sewing machine and being coupled to said needle bar oscillating mechanism, whereby selective composite pattern stitching with automatic needle position changing and automatic amplitude changing can be unitarily accomplished in an infinitely variable manner.

References Cited UNITED STATES PATENTS 3,041,988 7/1962 Fujita 112l58 3,053,207 9/1962 Adler 112158 3,221,686 12/1965 Gustin 112---158 PATRICK D. LAWSON, Primary Examiner. 

1. IN A ZIGZAG SEWING MACHINE HAVING A MOVING PART AND A NEEDLE BAR OSCILLATING MECHANISM, A BUILT-IN DEVICE FOR AUTOMATIC SELECTION OF DISC CAMS FOR COMPOSITE ZIGZAG PATTERN STITCHING, SAID DEVICE COMPRISING A GROUP OF NEEDLE POSITION CHANGING CAMS, A GROUP OF AMPLITUDE CHANGING CAMS, GROUPS OF CAM FOLLOWERS RESPECTIVELY CORRESPONDING TO SAID CAMS, TRANSMISSION MEANS DRIVEN BY SAID MOVING PART OF THE SEWING MACHINE TO TRANSMIT MOVEMENTS CONTROLLED BY SAID CAM FOLLOWERS TO SAID NEEDLS BAR OSCILLATING MECHANISM, AND A GROUP OF PATTERN SELECTION TAPPET CAMS FOR SELECTIVELY PLACING AT LEAST ONE OF SAID CAM FOLLOWERS IN OPERATIVE CONDITION, SAID GROUP OF TAPPET CAMS BEING ROTATED TO EFFECT AUTOMATIC AND SIMULTANEOUS CHANGING OF NEEDLE POSITION LINE AND AMPLITUDE, THEREBY TO CAUSE AUTOMATIC STITCHING OF A WIDE VARIETY OF COMPOSITE ZIGZAG STITCHING PATTERNS. 